The rockefeller university

Event Details

Type

Friday Lecture Series

Speaker(s)

Luciano Marraffini, Ph.D., assistant professor and head, Laboratory of Bacteriology, The Rockefeller University

Speaker bio(s)

Organisms of all kingdoms of life have developed immune systems with the ability to combat infection. Adaptive immune systems have the ability to create an antigenic memory of the invader to defend the cell more efficiently during recurring attacks. In archaea and bacteria, adaptive immunity is encoded by Clustered, Regularly Interspaced Short Palindromic Repeats (CRISPR) loci and their associated proteins (Cas). These loci create an antigenic memory through the incorporation of short (~40 bp) sequences from prokaryotic viruses (bacteriophages) and other mobile genetic elements during infection. Immunity is achieved by the transcription of these sequences into small antisense RNAs, known as crRNAs, that make base pair contacts with its target in the viral genome. This base-pair interaction specifies the site of cleavage of crRNA-guided Cas nucleases that destroy the invader to protect the cell. While many crRNAs target lethal bacteriophages and provide a fitness advantage to the bacterium, many others target antibiotic-resistant plasmids and other mobile genetic elements that are maintained as chromosomal or extra-chromosomal elements and that can carry beneficial genes for the host. Therefore these mobile genetic elements can be considered commensals and their destruction by CRISPR immunity can be detrimental to cell fitness. Dr. Marraffini will discuss how different CRISPR-Cas immune systems deal with this problem and the implications of tolerance of beneficial mobile genetic elements for the evolution of bacteria.

Dr. Marraffini, a native of Argentina, received his undergraduate degree from the University of Rosario in Argentina in 1998 and his Ph.D. from the University of Chicago in 2007, where he studied bacterial pathogenesis in the laboratory of Olaf Schneewind. He was a postdoc at Northwestern University from 2008 to 2010, when he joined Rockefeller as assistant professor. Dr. Marraffini received the 2015 Earl and Thressa Stadtman Scholar Award from the American Society for Biochemistry and Molecular Biology, was selected as a finalist for the 2015 Blavatnik National Award, and received a 2012 NIH Director's New Innovator Award. He is also a 2012 Rita Allen Foundation Scholar and a 2011 Searle Scholar and is the recipient of a 2010 RNA Society Award, a 2009 Nestle Award, and a 2008 Jane Coffin Childs Memorial Fund for Medical Research fellowship.

Open to

Public

Host

Cori Bargmann, Ph.D.

Reception

Refreshments, 3:15 p.m. - 3:45 p.m., Abby Lounge

Contact

Linda Hanssler

Phone

(212) 327-7714

Sponsor

Linda Hanssler
(212) 327-7714
lhanssler@rockefeller.edu

Readings

http://librarynews.rockefeller.edu/?p=3897